In a case where the pin terminal is packaged in the through hole at the circuit substrate so as to connect electrically with the electrode at the inner periphery, a compliant pin terminal 21 as exemplary in FIG. 11 may be used. The pin terminal 21 comprises a metallic terminal body 22, in which slits at an intermediate portion of the terminal body are expanded at the predetermined intervals so that two opposite divided portions 23 project outwardly to each other.
The pin terminal 21, when pressed into the through hole forming on the inner periphery thereof the electrode, is brought into press-contact at both the divided portions 23 with the inner surface of the through hole.
Hence, the pin terminal 21 is held in condition of being electrically connected to the through hole even without being soldered.
When such compliant pin terminal 21 is subjected to a lengthwise pulling force p, both the divided portions 23 are extended to make an interval (L.sub.2 in the drawing) therebetween smaller than an inner diameter of the through hole.
Therefore, the pin terminal 21 does not come into press-contact with the through hole, thereby creating the problem in that the electrical connection is not obtained and the pin terminal escapes from the through hole.
For the above, as shown in FIG. 12, it has been proposed that the body 24 of compliant pin terminal is formed in an about C-like shape in section and press-contactable with the inner surface of the through hole throughout the entire length to thereby strengthen resistance of the pin terminal against the pulling force p.
Besides this, it has been proposed that the terminal body 24 is approximately S-like-shaped in section (refer to FIG. 13) or M-like-shaped in section (refer to FIG. 14).
The terminal body 24 of such section has no portion to be deformed by the pulling force, resulting in that its resistance is strengthened against the pulling force.
The compliant pin terminal of such construction, however, is of entirely uniform form as well as the portions in press-contact with the electrode at the inner periphery of the through hole, whereby when the pin terminal is deformed by the external force, the portions in press-contact with the inner electrode also are deformed, resulting in that there is a fear that the pin terminal cannot be connected and fixed reliably and stably to the electrode at the inner periphery of the through hole.